1. Field of the Invention
The present invention relates to a catalyst performance recovery method in a reforming catalyst apparatus for producing reformed gas containing hydrogen by reacting fuel such as alcohols and hydrocarbons with water, and in particular, to a catalyst performance recovery method in a reforming catalyst apparatus, which is capable of recovering the catalyst performing without demounting the catalyst from the reforming catalyst apparatus and which is capable of ensuring the long service life of the reforming catalyst apparatus.
2. Description of the Related Art
A reforming catalyst apparatus for obtaining a reformed gas containing hydrogen by reacting a fuel including alcohol such as methanol with water on a catalyst by a steam reforming reaction is conventionally known. A fuel cell system which carries out power generation based on the electrochemical reaction by supplying the reformed gas including hydrogen, obtained in the reforming catalyst apparatus, and an oxidizing agent such as air, is also conventionally known.
In the reforming catalyst apparatus, performance of the catalyst has been recovered by replacing the catalyst to a brand-new catalyst when the catalyst has been degraded and the reforming efficiency of the catalyst has been lowered.
However, when the reforming catalyst apparatus is integrated in a complex system, frequent replacement of the catalyst is not easy and the recovery of the catalyst performance has not been easy. Accordingly, the reforming performance of the reforming catalyst apparatus thereby depends on the durability of the catalyst.
In particular, regarding a fuel cell vehicle, in which a fuel cell is installed, it is particularly difficult to unload the catalyst from the reforming catalyst apparatus. Generally, the fuel cell installed on the fuel cell vehicle is normally required to tolerate to hard driving conditions. Thus, in the fuel cell system, the short service life of the fuel cell causes a serious problem.
Japanese Unexamined Patent Application, First Publication No. 11-79702 discloses a method to supply air to the reforming catalyst when the reforming catalyst reaches a predetermined degradation degree, in order to recover the catalyst performance without demounting the catalyst from the reforming catalyst apparatus. However, when air is supplied to the reforming catalyst for activating and recovering the catalyst, a problem sometime arises that the reforming catalyst is deteriorated by oxidization with air.